/Engine/Plugins/Experimental/VirtualCamera/Source/VCamExtensions/Public/Hierarchies/ModifierHierarchyRules.h
An example use case is if you want to have a button menu which should procedurally generate sub-button menus depending on the modifiers in the component. One group could be a Lens group which groups together modifiers that e.g. modify focal distance, filmback, and FOV. The rules are defined generically enough so as modifiers are added or removed, the groupings also update accordingly.
[UCLASS](Programming/UnrealArchitecture/Reference/Classes#classdeclaration)(Abstract, Blueprintable, EditInlineNew) class UModifierHierarchyRules : public [UObject](API\Runtime\CoreUObject\UObject\UObject)